Important Information about Techniques

See Understanding Techniques for WCAG Success Criteria for important information about the usage of these informative techniques and how they relate to the normative WCAG 2.0 success criteria. The Applicability section explains the scope of the technique, and the presence of techniques for a specific technology does not imply that the technology can be used in all situations to create content that meets WCAG 2.0.

User Agent and Assistive Technology Support Notes

Description

The objective of this technique is to provide a way for people who are deaf
or otherwise have trouble hearing the dialogue in audio visual material to be
able to view the material. With this technique all of the dialogue and
important sounds are available in a text stream that is displayed in a
caption area.

With SMIL 2.0, separate regions can be defined for the video and the
captions. The captions and video playback are synchronized, with the caption
text displayed in one region of the screen, and the corresponding video
displayed in another region.

The example shows a <par> segment
containing a <video> and a
<textstream> tag. The systemCaptions
attribute indicates that the textstream should be displayed when the
user's player setting for captions indicates the preference for
captions to be displayed. The <layout>
section defines the regions used for the video and the captions.

Related Techniques

Tests

Procedure

Enabled caption preference in player, if present

Play file with captions

Check whether captions are displayed

Expected Results

#3 is true

If this is a sufficient technique for a success criterion, failing this test procedure does not necessarily mean that the success criterion has not been satisfied in some other way, only that this technique has not been successfully implemented and can not be used to claim conformance.